W3C Working Draft 07 March 2008

Table of Contents

Introduction

Incomplete draft: This document is an editor's copy that has no official standing and is incomplete. Particularly, the section WCAG 2.0 and MWBP Together is only an outline; WCAG 1.0 to MWBP is only partly filled out. It is subject to major changes and is therefore not intended for implementation. It is provided for review and feedback only. Please send feedback to public-bpwg-comments@w3.org (archive).

This page is part of a suite of related documents. Please refer to the “How to Use These Documents” section for more information. This document may be relevant if you have achieved WCAG compliance or are planning to do so.

This document describes how different WCAG checkpoints help Mobile Web users and how compliance with these checkpoints can help comply with the Mobile Web Best Practices 1.0 (MWBP). For content that already complies with WCAG at different levels, it outlines what may need to be done to comply with all of the MWBP.

There are two main sections. The first describes considerations for a strategy for upgrading content that meets WCAG towards meeting the MBWBP. The second describes the individual WCAG success criteria and how they related to the MWBP.

Extending from WCAG 2.0 to MWBP 1.0

This section provides guidance on planning an upgrade strategy from WCAG 2.0 compliance to MWBP 1.0. For content that already complies with WCAG 2.0, the following sections (one for each level of WCAG compliance) describe what is needed to achieve compliance with MWBP 1.0. For each BP, there are links to detailed information about how different success criteria relate to it. For each of the WCAG 2.0 levels already achieved, the BPs are classified in three broad categories representing the effort required, labelled for simplicity with keywords (nothing, something, everything):

Like the levels of compliance, the lists of BPs are cumulative and can be read independently of the other levels. The names of the BPs are links to the MWBP document. Names of WCAG success criteria are links to the detailed explanations in this document.

Level A Compliance Achieved

Nothing: content already complies with these BPs. Refer to the description of each success criterion for an explanation of how and in what way it meets the BP.

Something: more effort of some kind or a check, to comply with these BPs. Refer to the description of each success criterion for an explanation of how and in what way it partially or possibly meets the BP.

[Not evaluated yet]. When reviewing the document the following list should be ignored. During document editing, it contains CPs, SCs or BPs not yet evaluated. It is progressively reduced as items are studied and moved to the “something”, “nothing” and “everything” lists. It will not appear in the finished document.

Something: more effort of some kind or a check, to comply with these BPs. Refer to the description of each success criterion for an explanation of how and in what way it partially or possibly meets the BP.

Everything: start from scratch to comply with these BPs (all of the Everything list from Level A except those covered in Nothing and Something lists at this level). Use the links to read the description of each BP in the MWBP document and how to comply with it.

[Not evaluated yet]. When reviewing the document the following list should be ignored. During document editing, it contains CPs, SCs or BPs not yet evaluated. It is progressively reduced as items are studied and moved to the “something”, “nothing” and “everything” lists. It will not appear in the finished document.

Something: more effort of some kind or a check, to comply with these BPs. Refer to the description of each success criterion for an explanation of how and in what way it partially or possibly meets the BP.

Everything: start from scratch to comply with these BPs (all of the Everything list from Level AA except those covered in Nothing and Something lists at this level). Use the links to read the description of each BP in the MWBP document and how to comply with it.

[Not evaluated yet]. When reviewing the document the following list should be ignored. During document editing, it contains CPs, SCs or BPs not yet evaluated. It is progressively reduced as items are studied and moved to the “something”, “nothing” and “everything” lists. It will not appear in the finished document.

Individual WCAG 2.0 Success Criteria Compared

This section examines in turn each of the WCAG 2.0 success criteria where there is a relationship to the MWBP 1.0. The section following it describes the relationship of WCAG 1.0 to the MWBP 1.0. Those success criteria that are believed to have no relationship are listed seperately. Two main aspects are considered for each success criterion, “How does it especially help mobile users?” and “Does it give me MWBP 1.0 compliance?” which are introduced in a general way below.

How does it especially help mobile users? This paragraph describes how the Web Content Accessibility Guidelines help the general user in the mobile context above and beyond the special benefit for users with disabilities. Mobile users may benefit from the Web Content Accessibility Guidelines as do users with disabilities. However, this paragraph focuses on the extra benefits for the special needs of the general user of mobile devices. Checkpoints and guidelines that have no specific benefit for mobile users beyond that experienced by the user with disabilities is marked [no added benefit].

Does it give me MWBP 1.0 compliance? Many Web sites wish to ensure that their content is both mobile aware and accessible to users with disabilities by complying with both the MWBPs and WCAG. For a site that complies with WCAG this paragraph gives an idea of how much has already been achieved, and how much more could be achieved for little extra effort.

Many WCAG guidelines, checkpoints, and success criteria correspond directly to Mobile Web Best Practices 1.0 provisions, and complying with one automatically ensures compliance with the other, with no extra effort. For example, SC 1.4.1, “Use of Color” ensures compliance with BP [USE_OF_COLOR] “Ensure that information conveyed with color is also available without color”.

With other WCAG provisions, a little extra effort or simply considering the diversity of devices and environmental factors of the mobile context can help achieve compliance with a MWBP best practice. For example, @@xxx.

Other WCAG provisions prohibit the use of features that can cause problems in the mobile context. Complying with these guidelines or checkpoints ensures that some BPs simply do not apply. For example, @@xxx.

How does it especially help mobile users? WCAG requires a text equivalent for all non-text content, including images. This enables users in the mobile context to read content without downloading images.

How does it especially help mobile users? Mobile devices are often used in situations with significant background noise that makes it difficult to hear the audio track of multimedia content. It public places it may be socially unacceptable to listen to the soundtrack. Captions enable the user to understand the multimedia content in these situations.

Does it give me MWBP compliance?: Partially. It goes some way to complying with NON-TEXT_ALTERNATIVES. [@@ Whether this is necessary depends on whether the BP really requires text equivalents for multimedia; it links to the WAI Glossary definition].

How does it especially help mobile users? Many mobile devices have monochrome screens, often do not have good color contrast and are often used in less-than-ideal lighting conditions, and so like non-visual users or those with colour perception deficit they may be unable to percieve information conveyed by colour. This success criterion ensures that users who cannot perceive colour correctly for whatever reason will be able to understand and operate the content.

Does it give me MWBP compliance?: Yes, it should ensure compliance with USE_OF_COLOR without any further effort. It also helps to achieve compliance with BP STRUCTURE by ensuring that structural elements are used rather than colour.

How does it especially help mobile users? Mobile devices may have monochrome screens. Users in a mobile context may view the screen in unfavorable lighting conditions. Adequate color contrast will also help these users.

Does it give me MWBP compliance?: This checkpoint ensures compliance with COLOR_CONTRAST with no further effort.

How does it especially help mobile users? Content that moves, scrolls or auto-updates may be difficult to see with the reduced size of the mobile viewport. Blinking text may be especially difficult to see on the small screen and in poor lighting conditions.

How does it especially help mobile users? Mobile users typically navigate using the keypad. This can result in a large number of keystrokes to reach the main content of a page, especially if it is preceded by extensive navigation menus or lists of links. This SC also helps users skip large blocks of navigation links at the top of a page, a problem described in NAVBAR.

How does it especially help mobile users? Like users with no vision or limited field of vision, or cognitive disability, mobile users with small screens may have difficulty scanning and summarizing the overall content of a page. Perhaps the most useful item of metadata for a page is a descriptive page title, to provide a quick description of the content of a page.

Does it give me MWBP compliance?: Yes, this gives compliance with PAGE_TITLE with no further effort.

Tip: The title may be truncated in the mobile device as described in the BP. It may be useful to put the most important, differentiating information first, also helping screen reader users. Refer also to Long page title in “Summary of Experience of Content Features by Users” section.

How does it especially help mobile users?Users of mobile devices may suffer undue delay and cost as a result of following links due to network charges and device limitations, so it is important to inform them of the purpose of each link.

Does it give me MWBP compliance?: Possibly. It goes some way to meeting LINK_TARGET_ID but as the SC provides for indicating the link purpose in the context which is not contemplated by the BP, and in the title attribute or table cell header which are unlikely to be supported adequately by a mobile browser. As a result, content that conforms to this SC may not meet the BP. Also, the BP explicitly mentions file format (if not known to be supported by device), language, file size.

How does it especially help mobile users? Section headings allow ...easier adaptation of content where it needs to be divided into several pages, as well as potentially facilitating access to the sections of the document that a user is interested in.

Does it give me MWBP compliance?: Yes, this success criterion ensures compliance with STRUCTURE with no additional effort (although the title of the BP suggests a wider in scope).

How does it especially help mobile users?Change of user agent: Using a mobile device, launching a new application to render content is especially heavy on processor usage and battery life and should be avoided unless the user has requested it. Change of viewport: Many mobile devices cannot support more than one window and consequently, attempting to open one will have unpredictable results. Even where mobile devices do support multiple windows, their use is especially problematic. Opening new windows when an element receives focus is especially difficult for the mobile user. Change of focus: Navigation may be especially difficult with a reduced keyboard, and the reduced viewport of the mobile device may lead to the visual user becoming disoriented. Change of content: Auto-refreshing pages ... In a mobile environment they may expose the user to undue cost as a result of such a page being left open or put unnoticed into the background. also While redirection is a commonly employed mechanism, it must be remembered that redirection usually requires a round-trip to the browser. This adds to delay on slow links...

How does it especially help mobile users? Content adaptation and small screens may result in the visual relationship between labels and controls becoming lost. An explicit association enables the user agent to render them as intended.

Does it give me MWBP compliance?: Possibly. Some of the sufficient techniques for this success criterion ensure compliance with CONTROL_LABELLING.

How does it especially help mobile users? Similar to the benefit described for 3.3.2 Labels or Instructions but applicable to all user interface components. When the name, role, value, state, and properties is defined this potentially enables reformatting and transformation for the mobile context.

Does it give me MWBP compliance?: Possibly. Some of the sufficient techniques for this success criterion ensure compliance with CONTROL_LABELLING.

Document Information

Version: W3C Working Draft $Date: 2008/03/07 11:16:19 $Editor: Alan Chuter. Developed by the Education and Outreach Working Group (EOWG) and Mobile Web Best Practices Working Group (MWBP).